This is looking a lot like Refinements to Repeat Group Navigation! Please take a read through the specification @tomsmyth has proposed at https://github.com/opendatakit/roadmap/issues/19 and share any comments you have at Refinements to Repeat Group Navigation - #7 by workroommedia!
The major difference I see between what you've outlined and the proposal is that you're proposing to replace 'Go to End' with 'Add Group' rather than making group adding an addition. I can definitely see the logic in that.